Q: I was diagnosed with a pheochromocytoma. Is this something that could run in my family?
A: Pheochromocytomas are rare tumors of the adrenal gland, most of which are non-cancerous (benign). Tumors that develop in the adrenal gland can lead to an over production of the hormones that are normally released from this gland. The release of these hormones may cause symptoms in the body, such as high blood pressure, sweating, and increased heart rate. Some pheochromocytomas may not produce any symptoms.
At this time, we think that about one-half (50%) of all cases of pheochromocytomas are hereditary, meaning that the tumors form because of an underlying inherited alteration in a single gene. Researchers continue to find new genes that contribute to the inherited tendency for pheochromocytoma. The non-hereditary type, also known as sporadic pheochromocytoma, is thought to form as a result of one or more somatic gene changes that occur in the cells of the adrenal gland, possibly acting together with other risk factors that contribute to the growth of the tumor.
Because pheochromocytomas are often hereditary, it is important that anyone who is diagnosed with this type of rare tumor be evaluated by a genetics professional. Many patients with hereditary forms of pheochromocytomas will not have a family history of the disease. However, people who have hereditary pheochromocytomas may be at risk of developing other tumors, and a genetics evaluation can help to clarify these risks. During a genetics evaluation, your doctor and genetics counselor will review your personal and family medical history. The family history can help your genetics team to assess for features that may suggest an inherited tendency for tumors or other cancers, which may be part of a known hereditary syndrome (a syndrome is a group of symptoms that together are characteristic of a disease). Your genetics team will also provide counseling about the risks, benefits and limitations of having genetic testing.
Some hereditary syndromes that can predispose someone to pheochromocytomas are:
- Hereditary Paraganglioma and Pheochromocytoma syndrome (PGL/PCC) which can be caused by mutations in a number of genes: SDHA, SDHB, SDHC, SDHD, SDHAF2, MAX, TMEM127, and possibly KIF1B and EGLN1.
- Von Hippel-Lindau syndrome (VHL) caused by mutations in the VHL gene.
- Neurofibromatosis I (NF1) caused by mutations in the NF1 gene.
- Multiple Endocrine Neoplasia type 2 (MEN2) caused by mutations in the RET gene.
Learning that your pheochromocytoma was caused by an underlying genetic predisposition can help to clarify your risk of developing other tumors. It may also provide important information to your family members about their risks. For example, if an inherited gene alteration is identified in genetic testing, your close relatives, such as your children, siblings, and parents, would have a 50% chance of also having this gene alteration. Testing would be available for your family members to find out whether or not they are at risk for developing pheochromocytomas and possibly other tumors. Their doctors would recommend specific tests to monitor for tumors so that these could be detected early. Treatments for tumors or cancers are often more effective if the disease is found early.
The Paraganglioma-Pheochromocytoma Genetics Group is a collaborative initiative of the Dana-Farber Cancer Genetics and Prevention Program and the Brigham and Women's Endocrine Division involving endocrinologists, geneticists, oncologists, and genetic counselors dedicated to providing patients with access to personalized hereditary risk evaluation, genetic testing, recommendations for screening and prevention, and long-term follow-up.